For some time now, lower limb ulcers of diabetics have been a frequent reason for consultation to both the general practitioner and the specialist. Ulcers consist of the loss of epidermis and all or part of the dermis, also compromising the subcutaneous cellular tissue and muscle for several degrees of depth. These are formed because of a combination of factors occurring in the person such as lack of sensation in the foot, poor circulation, foot deformities, irritation (such as friction or pressure), and trauma. More particularly, those suffering from diabetes for a long time exhibit a high probability of developing neuropathy (damage to one or more nerves) on the lower limbs because of high levels of blood sugar, resulting in a reduction or lack of sensation in said area, which promotes the formation of ulcers.
Once a person has an ulcer, their quality of life is diminished as it is a painful wound that tends to easily become infected, despite appropriate care, as well as limiting their ability to move. This is a wound to which one should pay close attention because depending on its progress and severity, sometimes hospitalization of the affected person is necessary, and in more severe cases, amputation of an ulcer member, when it puts the patient's life at risk (the wound becomes a matter of life or death).
So far, the traditional management of this type of skin wounds is mainly based on the mechanical debridement of the affected area, topical application of substances and/or medicaments to promote healing, bandage over the affected area, and patient's rest. Among such used substances are antiseptics, antibiotics, topical vitamins, dextranomers, benzoyl peroxide, local vasodilators, etc., which do not provide the patient with reliable results and fast improvement.
There are natural remedies made from plant and roots extracts, which exhibit good qualities for skin regeneration and care. One of these remedies is obtained from the Hydrocotyle asiatica L. plant whose common name is centella asiatica or gotu kola, which is mainly composed by triperpenic compounds (asiatic acid, asiaticoside, madecassoside, and madecassic acid), tannins, oils, mucilages, pectins and phytosterols. Generally, the leaves of centella asiatica are used in infusions, but also its extract is used in the manufacture of creams and ointments.
In the prior art, several compositions to promote better healing of skin wounds such as ulcers or sores, which include centella asiatica extract as one of their main components can be found. Such is the case of European Patent Application No. EP 1 221 325A2, wherein a topical composition employing centella asiatica and ginseng extracts for skin wound healing as well as a process for the preparation thereof are described. Said composition comprises centella asiatica extract in 0.01-1% by weight and ginseng extract in 0.01-0.5% by weight as active agents. Likewise, depending on the formulating agents to be added to the composition, it may have a consistency of a gel or cream.
A drawback of the above described composition is that among its active and formulating agents, no antibiotic agent is found to prevent and fight infections of the skin wounds. Despite the curative qualities of ginseng, it would be desirable if such a composition included an active agent having a higher skin healing and regeneration activity.
Another example of compositions of this type is found in U.S. Patent Application No. US 2010/0062085A1, which describes a composition used to regenerate damaged skin tissue and, more specifically, it is used for the treatment of scars consequent upon surgeries. Said composition essentially comprises Bulbine frutescens, centella asiatica and one phenol extracted from olive oil (oleuropein). The percent of centella asiatica in the composition is from 0.45% to 0.55% mass/mass while the percent of Bulbine frutescens in the composition is from 9.9% to 11% mass/mass. The formulations obtained from this composition can be in the form of an ointment, cream, lotion, paste, gel, spray, or oil.
Although it is described that oleuropein has antiseptic properties (antifungal, antibiotic and anti-inflammatory), its spectrum is limited, so it would be advisable that said composition included a broad-spectrum antibiotic as an additional active agent.
Another example of compositions including centella asiatica is the composition described in U.S. Patent Application No. US 2004/0131706 A1, which is used for treating skin injuries caused by several factors such as viral diseases, fungi, allergic reactions etc., comprising natural or synthetic extracts from plants such as Centella asiatica, Mahonia aquifolium, Viola tricolor, among others. The weight percent in the composition of Centella asiatica is from 1 to 10%, of Mahonia aquifolium is from 1 to 10%, and of Viola tricolor is from 1 to 10%. Unlike other compositions of the prior art, said composition does not use zinc oxide.
As noted, the above described composition does not have an antibiotic among its active ingredients to prevent bacterial infections and promote a fast regeneration of new tissue.